Self-powered towing servomechanism

Abstract

A wheeled tailer power unit includes a self-powered, self-contained towing servomechanism that permits selective towing and control of a trailing vehicle by a leading vehicle in the absence of a power transmitting and control umbilical between the leading vehicle and the trailer power unit, A controller included in the trailer power unit measures the relative displacement of the unit and the leading vehicle and communicates to a unit control and drive means appropriate signals to operate variable torque transmitting drive means operating the respective wheels of the trailer power unit.

Therefore, in view of the foregoing, I claim: 
     
       1. An obedient self-powered and self-controlling slave vehicle for interposition between a leading master vehicle and a towed trailer unit; said slave vehicle having a body and independent suspension means for two independently driven ground engaging wheels, said ground engaging wheels each having an axis of rotation lying in a vertical plane common to both axes and which extends transversely of said slave vehicle; individual suspension means for said respective ground-engaging wheels permitting oscillations of said respective axes of said respective ground wheels in said substantially vertical plane to the substantial exclusion of movements of said axes of said respective ground wheels in any other direction;   a power supply mounted on said slave vehicle;   controllable variable torque transmitting means interposed in independent drive means from said power supply to said respective ground engaging wheels;   control means carried by said slave vehicle and controlling said variable torque transmitting means, said control means being operatively associated with actuator means and attached to said master vehicle by attachment means and actuated by said actuator means for it to follow the omnidirectional movement of said actuator means, and thus movements of said actuator means relative to a reference point on said slave vehicle, to provide selective steering, acceleration and braking of said slave vehicle duplicating movements of said master vehicle in the absence of a mechanical interconnection between said vehicles; and   pivot means affixed to said slave vehicle body, said pivot means including first and second members providing for relative rotation between said members, one of said members being rigidly and immovably affixed to said slave vehicle body, the other of said members being rigidly attachable to said towed trailer at a leading end of said trailer, said trailer having ground engaging wheels at a trailing end of said trailer, said first and second members being rotatable relative to each other about an axis intersecting a centroid of said respective axes of rotation of said respective ground engaging wheels of said slave vehicle.   
     
     
       2. The obedient, self-powered and self-controlling slave vehicle of claim 1, in which one of said first and second members of said pivot means is detachably affixed to said towed trailer, thus permitting detachment of said slave vehicle from said towed trailer and subsequent connection of said slave vehicle to another said towed trailer. 
     
     
       3. The obedient, self-powered and self-controlling slave vehicle of claim 1, in which the axis of rotation of said first and second members of said pivot means is a vertical axis intersecting said centroid of said respective axes of rotation of said respective ground engaging wheels of said slave vehicle. 
     
     
       4. An obedient self-powered and self-controlling slave vehicle according to claim 1, further including means to provide controllable differential, reversible thrust to said ground-engaging wheels for selective and respective acceleration, deceleration, steering and stopping of said trailer power unit, said thrust providing means being responsive to movement of a controller communicating with a position indicating member disposed on said leading master vehicle, said thrust providing means including an internal combustion engine controllable by an engine throttle control and communicating through a gear body with respective variable torque transmitting means, and said variable torque transmitting means controlling output from said internal combustion engine and communicating in a closed, negative feedback loop with respective bi-directional hydraulic motors, said hydraulic motors providing thrust to said ground-engaging wheels; a controller comprising a pair of push/pull cables interconnecting via respective fixed reference points on said trailer power unit the position indicating member disposed on said leading master vehicle and respective torque control levers disposed on respective controllable variable torque transmitting means;   an engine control and brake actuator system interconnecting between said controller and said torque control levers, said engine control and brake actuator system being a vacuum servomechanism operable in response to vacuums produced in an intake manifold of said internal combustion engine, said engine control and brake actuator system comprising a linear displacement element interconnecting the intake manifold and a rigid brake actuator link having an actuator link bearing pad disposed at an end thereof, said engine control and brake actuator system including a push/pull cable interconnecting said engine throttle control and said brake actuator link; and   a supplemental braking system operably communicating with said engine control and brake actuator system, said supplemental braking system including a brake control lever attached to a rigid response link having a response link bearing pad disposed at an end thereof, said response link bearing pad and said actuator link bearing pad being disposed in displaced face-to-face relationship for selective operation of said braking system in response to linear movement of said linear displacement element, first and second engine control levers being pivotally attached to said brake actuator link and interconnecting the position indicating member and the respective torque control levers.   
     
     
       5. An obedient, self-powered and self-controlling slave vehicle according to claim 1, wherein said attachment means comprises a trailer power unit connector including a connector stem which extends into a central body, and said suspension means comprises said central body, and thrust and radial bearings disposed below the trailer power unit connector on the top of said central body and within said central body about said connector stem, said connector stem being free to rotate laterally with said central body, chassis frame members extending from each side of said central body, said frame members being pivotally connected to said central body at one end and fixedly attached to wheel frames at the opposite end, springs being fixedly attached between the unit body and said frame members proximate to said wheel frames. 
     
     
       6. An obedient, self-powered and self-controlling slave vehicle according to claim 1, further including an engine control and brake actuator system interconnecting said control means and a torque control of said variable torque transmitting means, said engine control means and brake actuator system being a vacuum servomechanism operable in response to vacuums produced in an intake manifold of an internal combustion engine comprising said power supply, and a supplemental braking system operably communicating with said engine control and brake actuator means. 
     
     
       7. An obedient, self-powered and self-controlling slave vehicle according to claim 6, wherein said engine control and brake actuator system comprises a linear displacement element interconnecting the intake manifold and a rigid engine control and brake actuator link having an actuator link bearing pad disposed at an end thereof, and said supplemental braking system includes a brake control lever attached to a rigid brake response link having a response link bearing pad disposed at an end thereof, said response link bearing pad and said actuator link bearing pad being disposed in displaced face-to-face relationship for selective operation of said braking system in response to linear movement of said linear displacement element, first and second engine control levers being pivotally attached to said engine control and brake actuator link and interconnecting the position indicating member and the respective torque control levers. 
     
     
       8. An obedient, self-powered and self-containing slave vehicle according to claim 7. wherein said engine is controllable by an engine throttle control and said engine control and brke actuator system includes a push/pull cable interconnecting said engine throttle control and said brake actuator link.